Below is a figure that describes the various corn growth stages during reproductive growth (from silking to black layer). The estimated number of days between growth stages will help give corn producers an idea of the progression of the crop for management decisions, specifically irrigation termination.
🌽 Reproductive (R) Stages
- R1 (Silking): Silks emerge and rise through the husks. Essential for pollination; silks stay receptive for ~2 weeks
- R2 (Blister): Kernels are white, soft, and filled with clear fluid ~10–14 days after silking
- R3 (Milk): Roughly 18–22 days post-R1, kernels‘ fluid turns milky as starch builds, moisture ~80%
- R4 (Dough): Starch thickens to pasty dough (~24–28 days after R1), kernels ~70% moisture
- R5 (Dent): Most kernels dent, a hard starch line forms at the top (~35–42 days after R1)
- R6 (Physiological Maturity / Black Layer): About 55–65 days after R1, a black layer forms at kernel tips—signaling maximum dry matter and maturity (~30–35% moisture)
Additional information on growth staging corn can be found in this Land Grant Press Article: Visual Guide to Corn Growth Stages
Sources:
nutrien-ekonomics.com+4lgpress.clemson.edu+4clemson.edu+4 clemson.edu+2lgpress.clemson.edu+2cropscience.bayer.us+2 clemson.edu+2lgpress.clemson.edu+2cropscience.bayer.us+2 clemson.edu+2lgpress.clemson.edu+2cropscience.bayer.us+2 blogs.clemson.edu+12lgpress.clemson.edu+12clemson.edu+12 morningagclips.com+3lgpress.clemson.edu+3clemson.edu+3
